The new Geometry Nodes tools are coming out thick and fast with the daily builds of Blender 2.93. Very exciting time to be a Blender user!
Both of these scenes are generated with minimal destructive modelling - only modelling 1 or 2 petals per flower. The distribution and manipulation is all done within the nodes. The sunflowers render is unedited and the basket render is just flipped and colour graded. All extra smudge and dust effects etc to make it feel painterly are done in the scene.
Would I generally go for a more manual process that just uses Geo Nodes for parts it excels in? Yes. But this was a technical test to see what could be done with the new system in its current state of development.